Your browser does not support inline frames or is currently configured not to display inline frames.

Douglas DC3

A weatherbeaten C-47A Skytrain of the Army Air Force 9th Troop Carrier
Command on 6 June 1944.

The word ubiquitous has
been associated with a number of aircraft in wide-scale use during
World War II, but the most ubiquitous of all has to be the Douglas
DC-3/C-47 Skytrain. This superlative wartime transport aircraft,
produced in greater numbers than any other in this category, with
almost 11,000 manufactured by the time production ended in 1945, but
whatever name you choose, it can be spelled 'dependable', for this was
the secret of the type's greatness and enduring service life.

Its design originated
from the DC-2/DST/DC-3 family of commercial transports that followed in
the wake of the DC-1 prototype which flew for the first time on 1 July
1933. The US Army, had gained early experience of the basic aircraft
after the acquisition of production DC-2s in 1936, followed by more
specialised conversions for use as cargo and personnel transports. In
August 1936 the improved DC-3 began to enter service with US domestic
airlines, its larger capacity and enhanced performance making it an
even more attractive proposition to the US Army, which very soon
advised Douglas of the changes in configuration which were considered
desirable to make it suited for operation in a variety of military
roles. These included the provision of more powerful engines, a
strengthened rear fuselage to cater for the inclusion of large cargo
doors, and reinforcement of the cabin floor to make it suitable for
heavy cargo loads. Much of the bagic design work had already been
completed by Douglas, for a C-41 cargo prototype had been developed by
the installation of 1,200 hp (895 kW) Pratt & Whitney Twin Wasp engines
in a C-39 (DC-2) fuselage. Thus, when in 1940 the US Army began to
issue contracts for the supply of these new transport aircraft under
the designation C-47, the company was well prepared to meet the
requirements and to get production under wily. The only serious problem
was lack of productive capacity at Santa Monica, where European demands
for the DB-7 light bomber had already filled the factory floor,
resulting in the C-47 being built in a new plant at Long Beach,
California.

Initial production
version was the C-47, of which 953 were built at Long Beach, and since
the basic structural design remained virtually unchanged throughout the
entire production run, this version will serve for a description of the
structure and powerplant. Of all-metal light alloy construction, the
cantilever monoplane wing was set low on the fuselage, and provided
with hydraulically operated split type trailing-edge flaps. The
ailerons comprised light alloy frames with fabric covering. The
fuselage was almost circular in cross-section. The tail unit was
conventional but, like the ailerons, the rudder and elevators were
fabric- covered. Pneumatic de-icing boots were provided on the leading
edges of wings, fin and tailplane. Landing gear comprised a
semi-retractable main units which were raised forward and upward to be
housed in the lower half of the engine nacelles, with almost half of
the main wheels exposed. The powerplant of the C-47 comprised two Pratt
& Whitney R-1830-92 Twin Wasp engines, supercharged to provide an
output of l,050 hp (783 kW) at 7,500 ft (2285 m), and each driving a
three-blade constant-speed metal propeller. The crew consisted of a
pilot and co-pilot/navigator situated in a forward compartment with the
third member, the radio operator, in a separate compartment.

The all-important cabin
could be equipped for a variety of roles. For the basic cargo
configuration, with a maximum load of 6,000 Ibs (2722 kg), pulley
blocks were provided for cargo handling and tie-down rings to secure it
in flight. Alternative layouts could provide for the transport of 28
fully-armed paratroops, accommodated in folding bucket type seats along
the sides of the cabin or for 18 stretchers and a medical team of
three. Racks and release mechanism for up to six parachute pack
containers could be mounted beneath the fuselage, and there were also
under fuselage mountings for the transport of two three-blade
propellers.

The first C-47s began
to equip the USAAF in 1941, but initially these were received only
slowly and in small numbers, as a result of the establishment of the
new production line at Long Beach which, like any other, needed time to
settle down to routine manufacture. With US involvement in World War II
in December 1941, attempts were made to boost production, but in order
to increase the number of aircraft in service as quickly as possible
DC-3s already operating with US airlines, or well advanced in
construction for delivery to operators, were impressed for service with
the USAAF.

As Douglas began to
accumulate contracts calling for production of C-47s in thousands, it
was soon obvious that the production line at Long Beach would be quite
incapable of meeting requirements on such a large scale, so a second
production line was established at Tulsa, Oklahoma. The first model to
be built at Tulsa was the second production version, the C-47A, which
differed from the C-47 primarily by the provision of a 24 volt, in
place of a 12 volt electrical system. Tulsa was to build 2,099 and Long
Beach 2,832 of the type, 962 of them being delivered to the RAF which
designated them Dakota IIIs. Last of the major production variants was
the C-47B, which was provided with R-1830-90 or -90B engines that had
two-stage superchargers to offer high altitude military ratings of
1,050 hp (783 kW) at 13,100 ft (3990 m) or 900 hp (671 kW) at 17,400 ft
(5305 m) respectively. These were required for operation in the
China-Burma-India (CBI) theatre, in particular for the 'Hump'
operations over the 16,500 ft (5030-m) high Himalayan peaks, carrying
desperately needed supplies from bases in India to China. Long Beach
built only 300 of the model, but Tulsa provided 2,808 C-47Bs plus 133
TC-47Bs which were equipped for service as navigational trainers. The
UK was to receive a total of 896 C-47Bs, which in RAF service were
designated Dakota IV.

The availability of
such large numbers, in both US and British service, meant that it was
possible to begin to utilise the C-47s on a far more extensive basis.
The formation in mid-1942 of the USAAF's Air Transport Command saw the
C-47s' wide-scale deployment as cargo transports carrying an almost
unbelievable variety of supplies into airfields and airstrips which
would have been complimented by the description 'primitive'. Not only
were the C-47s carrying in men and materials, but were soon involved in
a two-way traffic, serving in a casualty-evacuation role as they
returned to their bases. These were the three primary missions for
which these aircraft had been intended when first procured (cargo,
casualty evacuation and personnel transports). However, their
employment by the USAAF's Troop Carrier Command from mid-1942, and the
RAF's Transport Command, was to provide two new roles, arguably the
most important of their deployment in World War II, as carriers of
airborne troops. The first major usage in this capacity came with the
invasion of Sicily in July 1943, when C-47s dropped something
approaching 4,000 paratroops. RAF Dakotas of Nos. 31 and 194 Squadrons
were highly active in the support of Brigadier Orde Wingate's Chindits,
who infiltrated the Japanese lines in Burma in an effort to halt their
advance during the winter of 1942-3, their only means of supply being
from the air. Ironically, Wingate (by then a major general) died on 24
March 1944 when a Dakota in which he was a passenger crashed into cloud
camouflaged jungle-clad mountains.

The other important
role originated with the C-53 Skytrooper version, built in
comparatively small numbers as the C-53B/-53C/-53D. Seven C-53s
supplied to the RAF were redesignated Dakota II. These were more nearly
akin to the original DC-3 civil transport, without a reinforced floor
or double door for cargo, and the majority had fixed metal seats to
accommodate 28 fully-equipped paratroops. More importantly, they were
provided with a towing cleat so that they could serve as a glider tug,
a feature soon to become standard with all C-47s, and it is in this
capacity that they served conspicuously in both USAAF and RAF service
during such operations as the first airborne invasion of Burma on 5
March 1944 and the D-Day invasion of Normandy some three months later.
In this latter operation more than 1,000 Allied C-47s were involved,
carrying paratroops and towing gliders laden with paratroops and
supplies. In the initial stage of this invasion 17,262 US paratroops of
the 82nd and 101st Airborne Divisions and 7,162 men of the British 6th
Airborne Division were carried across the English Channel in the
greatest airlift of assault forces up to that time. Not all, of course,
were carried in or towed by C-47s, but these aircraft played a most
significant role in helping to secure this first vital foothold on
European soil. In less than 60 hours C-47s alone airlifted more than
60,000 paratroops and their equipment to Normandy.

Other C-47 variants of
World War II included the XC-47C, prototype (serial 42-5671) of a
projected version to be equipped as a floatplane or, as was the
prototype, with convertible amphibious floats of all-metal
construction, these single-step twin Edo Model 78 floats each had two
retractable wheels, and housed a 300 US gallon (1136 litre) fuel tank.
While this version was not built as such by Douglas, a small number of
similar conversions were made by USAAF maintenance units for service in
the Pacific. Douglas were also contracted to build 131 staff transports
under the designation C-117, these having the airline-standard cabin
equipment of a commercial DC-3, plus the improvements which were
current on the C-47. Their numbers, however, had reached only 17 (one
C-ll7B built at Long Beach and 16 C-117As from Tulsa) when VJ-Day
brought contract cancellation. The requirement for a large-capacity
high-speed transport glider, to be towed by a C-54, resulted in
experimental conversion of a C-47 to serve in this role under the
designation XCG-17. Early tests had been conducted with a C-47 making
unpowered approaches and landings to confirm the feasibility of the
project, followed by a series of flights in which one C-47 was towed by
another. For take-off the towed aircraft used some power, but shut down
its engines when airborne. Conversion of a C-47 to XCG-17 configuration
began after completion of these tests, with engines, propellers and all
unnecessary equipment removed, and the forward end of the engine
nacelles faired over. This was undoubtedly aerodynamically inefficient,
and contributed to a reduction in performance of the XCG-17, but it was
a USAAF requirement that any production aircraft should be capable of
easy reconversion to powered C-47s. Despite any inefficiency the the
embryo cargo glider had a successful test programme, demonstrating a
towed speed of 290 mph (467 km/h), stalling speed of only 35 mph (56
km/h) and a glide ratio of 14:1. Payload was 14,000 lbs (6350 kg),
permitting the transport of 40 armed paratroopers. No production
aircraft were built, however, as a result of changing requirements.

In addition to the
C-47s which served with the USAAF and the RAF, approximately 600 were
used by the US Navy. These comprised the R4D-1(C-47), R4D-3 (C-53),
R4D-4 (C-53C), R4D-5 (C-47A), R4D-6 (C-47B) and R4D-7 (TC-47B). US Navy
and US Marine Corps requirements resulted in several conversions with
designations which include the R4D-5E/-6E with special-purpose
electronic equipment; the winterised and usually ski-equipped
R4D-5L/-6L; the R4D-4Q/-SQ/-6Q for radar countermeasures; cargo
versions re-equipped for passenger carrying as the R4D-5R/-6R; the
air-sea warfare training R4D-5S/-6S; the navigational training
R4D-5T/-6T; and the VIP-carrying R4D-5Z/-6Z. R4Ds were used initially
by the Naval Air Transport Service that was established within five
days of the attack on Pearl Harbour, equipping its VR-1, VR-2 and VR-3
squadrons, and soon after this by the South Pacific Combat Air
Transport Service which provided essential supplies to US Marine Corps
units as they forced the Japanese to vacate islands which stretched
across the seas that led like stepping stones to that nation's home
islands.

In addition to US
production, the type was built in the USSR as the Lisunov Li-2 (2,000
examples or more) and in Japan as the Showa (Nakajima) L2D (485
examples).

C-47s had been involved
from the beginning to the end of World War II, and that is but a small
portion of their history in both military and civil service. Since VJ-Day
military C-47s have supported the Berlin Airlift, Korean and Vietnam
wars, to mention only major operations. It would not be too far from
the truth to suggest that in the 42 years to 1982 there have not been
many military actions or major civil disasters in which the enduring
C-47 has not played some part.

Specifications (Douglas
DC-3/C-47A Skytrain)

Type: Three Seat
Military Transport, Paratroop Carrier & Glider Tug

Accommodation/Crew:
Pilot, Co-pilot/Navigator (side-by-side with dual controls) and Radio
Operator

Design: The
Douglas Aircraft Company Incorporated based on the DC-2 design by
Donald W. Douglas

Manufacturer:
The Douglas Aircraft Company Incorporated with factories in Santa
Monica (California), Long Beach (California), Tulsa (Oklahoma) and
Oklahoma City (Oklahoma)

Fuel: (DC-3
civil) Two main fuel tanks were located forward of the centre-section
spar each with a capacity of 210 US Gallons (794 litres) and two
auxiliary fuel tanks aft of the spar each with a capacity of 201 US
Gallons (760 litres). (C-47 military) Two main fuel tanks wer located
forward of the centre-section spar each with a capacity of 202 US
Gallons (763.7 litres) and two auxiliary fuel tanks aft of the spar
each with a capacity of 200 US Gallons (756.2 litres). Each engine was
served by a separate fuel system but cross-feed permits both engines to
be supplied by either set of tanks in case of an emergency. Some
military aircraft had provision for a single auxiliary fuel tank in the
fuselage.

Armament:
(AC-47D) The 1965 designation for gunship conversions with three 7.62
mm (0.30 in) General Electric Miniguns firing through the fourth and
fifth windows and from the open door on the port side of the fuselage.
Some of the Soviet aircraft were armed as well. Apart from the above
exceptions all other aircraft had no armament.

Equipment/Avionics:
Full radio equipment includes radio compass, marker beacon receiver
and receivers for localised and glide-path reception for the
instrument-landing equipment. Glider-towing cleat in tail. De-icing
equipment includes airscrew anti-icing system, rubber de-icer shoes on
outer wings, tailplane and fin leading edges and alcohol-type
windscreen de-icer. Oxygen equipment. Some aircraft were equipped with
H2S radar for training purposes and others had "Rebecca" navigational
radar for use as pathfinders.

Fuselage/Cargo Area:
Main cargo hold equipped with snatch block, idler pulley and tie-down
fittings for cargo handling. Large freight door on port side. Cargo
load of 6,000 lbs (2725 kg) that may include three aero-engines on
transport cradles, or two light trucks. Folding seats down sides of
cabin for 28 fully-armed airborne or parachute troops. Alternatively
fittings for eighteen stretchers together with provision for a medical
crew of three. Racks and release mechanism for six parachute pack
containers under fuselage. Also under the fuselage are fittings for
carrying two three-bladed airscrews.

Wings/Fuselage/Tail
Unit: The wings were of a low-wing cantilever monoplane design with
a rectangular centre-section and tapering out sections with detachable
wing-tips and Douglas cellular multi-web construction. The ailerons
were fabric covered with controllable trim-tabs in the starboard
aileron. Hydraulically operated all-metal split trailing-edge flaps.
The fuselage was an almost circular-section structure built up of
transverse frames of formed sheet longitudinal members of extruded bulb
angles, with a covering of smooth sheet metal. The Tail Unit was of the
cantilever monoplane type with The tail-plane and fin of multi-cellular
construction. The rudder and elevators have aluminium-alloy frames and
fabric covering and are aerodynamically and statically balanced. There
are trim-tabs in all the control surfaces.